Cellular network system and method

ABSTRACT

In a cellular network system, an add-on base station comprising: A. a first channel for connecting to a customer&#39;s phone; B. a second channel for connecting to a network; C. circuits for connecting the customer&#39;s phone to a destination on the network; and D. billing means for collecting a payment for services related to connecting the customer&#39;s phone to the network. The customer&#39;s phone may be connected through a wireless link. A method to establish a link between a caller and an addressee comprising the steps of: A. The caller sends a request to a cellular center requesting to connect to a specific addressee, using a message encrypted with the public key of the center; B. the center decrypts the message, identifies the caller and the addressee; C. the center composes a message for the addressee and encrypts it with the public key of the addressee. The message is then sent to base stations; D. the base station transmits the message “as is” or in a modified form; E. only the designated addressee will be capable to decrypt the message, and will be thus notified of the attempted connection.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED R&D

[0001] There was no Federal sponsoring for the present invention,therefore there are no rights deriving therefrom.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] The present application is related to the application No.PCT/IL99/00438 filed on Aug. 12, 1999.

FIELD OF THE INVENTION

[0003] This invention relates to systems for creating cellulardistributed networks and methods for controlling their installation andoperation. The invention concerns in relates in particular to add-onbase stations that allow the creation or expansion of such networks.

BACKGROUND OF THE INVENTION

[0004] Currently, it is relatively expensive, time consuming anddifficult to install cellular networks. The network installation isespecially problematic in highly populated urban areas.

[0005] Cellular systems use base stations to establish an RF linkbetween each user in the cell and the cellular wired network. These basestations use a relatively high transmit power, to overcome propagationlosses in order to achieve a reliable link. This high RF power, however,may be harmful to people nearby. Moreover, it may interfere with otherelectronic equipment. These may be part of the reasons why people objectto the installation of base stations in populated areas.

[0006] In highly populated areas there is a need for more base stations,more closely located to each other. As more users are to be served in aspecific area, the cells are made smaller, and more base stations haveto be installed.

[0007] Therefore, the objection of the public to the installation ofadditional base stations is a serious impediment to the development of acellular network.

[0008] Moreover, in highly populated areas the real estate is usuallyexpensive. It requires a large investment to install base stations inthese areas and to install the wiring as required. Once the basestations are installed, it may be required to service them.

[0009] One can appreciate the high maintenance cost for a multitude ofbase stations located in a highly populated urban area.

[0010] Heretofore, a large distributed network required a plurality oflarge switchboards to make all the required connections. As the numberof cells and users increase, the number and complexity of switchboardsincreases as well. There is a large number of concurrent calls that haveto be supported. This further increases the cost of setting up andoperating a cellular network.

[0011] It is an objective of the present invention to facilitate theinstallation and expansion of distributed cellular networks, especiallyin highly populated urban areas.

[0012] Another problem in cellular systems is the relatively hightransmitted power of the mobile phones. The transmit antenna is close tothe user's head, and the RF radiation may have undesirable effects.

[0013] As the distance to a base station increases, the mobiletransmitter has to transmit at a higher power. Thus, from the radiationhazard viewpoint, it would be desirable to have more base stations, moreclosely related. This would allow transmission at lower power. There areproblems to adding base stations, however, as detailed above.

[0014] It is another objective of the present invention to achieve areduction in the mobile phone transmit power, by using more basestations that are more closely located to each other.

SUMMARY OF THE INVENTION

[0015] According to the present invention, there is provided a systemand method that facilitate the installation of distributed cellularnetworks, especially in developed and highly populated urban areas,using a structure and method implemented with an add-on base station.This may also allow the public at large to participate in providingtelecommunication services.

[0016] Basically, the system uses the existing infrastructure, forexample cable TV, Internet connections and phone networks to provideadditional wireless coverage.

[0017] According to the invention, the public can participate inproviding the function of add-on base stations. These public-owned andpublic-operated base stations complement a cellular network, thusincreasing the density of base stations to provide better coverage withsmaller cells.

[0018] A novel network structure allows the inclusion of thesepublic-operated base stations within a distributed cellular network.Call coordination means are used to control the operation of thenetwork.

[0019] A distributed network may incorporate the novel base stationswithin a conglomerate of cellular nets, wired telephone networks and anInternet.

[0020] A novel feature of the base station is an unique property of eachdevice. This allows its use as an add-on base station. In prior art,each phone had an unique identity, however the base stations had nounique properties. Each base station in prior art was distinguishedbased on its fixed location and wiring; there were no distinguishingmeans in the base station itself. In the novel approach according to thepresent invention, however, there are base stations that are add-onunits to be added to a network by various persons or firms.

[0021] The location of each such unit is not known a priori; its veryexistence has to be announced to the network. A base station with anunique identity allows the network to keep track of the addition of eachnew base station.

[0022] Each novel base station includes means for providing an incentiveto the public to acquire and operate them, so as to enhance the cellularnetwork. Using an economic incentive (for example, payment to the ownerof a base station for use of his/her device) will stimulate people tooperate these base stations. Thus, parts of the public will no moreobject to the installation of base stations. Rather, people willparticipate in the development of the cellular network.

[0023] According to another aspect of the invention, a payment system isdisclosed, that uses digital tokens or prepaid digital documents. Tokensmay be downloaded from a center, and the whole process may be madetransparent to the user.

[0024] Using a multitude of base stations, each for a small area, allowsto reduce the transmit power of each station. Thus, people will nolonger have to worry about the harmful effects of RF radiation. It maybe easier to obtain licenses to operate base station that use a lowertransmit power.

[0025] Moreover, it is possible to achieve a reduction in the mobilephone transmit power, by using more base stations that are more closelylocated to each other.

[0026] Furthermore in accordance with the invention, the object isbasically accomplished by using the existing telecommunicationinfrastructure that is available in developed areas. In these areas,there are available a large number of telephone lines as well asInternet links. These telecommunication facilities are not used all thetime. Provided the right incentive, people will offer these facilitiesfor other people's use in cellular links.

[0027] Heretofore, a large distributed network required a plurality oflarge switchboards to make all the required connections.

[0028] A novel approach uses a cellular coordination center that doesnot perform the actual call switching.

[0029] Rather, the new center just provides the information required formaking a call. Thus the workload on the center is greatly reduced.Smaller, simpler and lower cost switchboards may be used.

[0030] In some cases, the switchboards may be eliminated altogether. Afirst user is given an Internet address of the other party and mayconnect it directly. This achieves a direct link from one base stationto another, through IP. It may also be possible to connect users throughthe same base station. Prior art teaches how to connect two computersthat are located at fixed locations. The present invention discloses astructure and method for connecting mobile units, using a center forcoordinating the connection.

[0031] The technology in the present disclosure may be used for thetransmission of voice, data, multimedia or a combination thereof.

[0032] Further objects, advantages and other features of the presentinvention will become obvious to those skilled in the art upon readingthe disclosure set forth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

[0033]FIG. 1 illustrates a distributed cellular network

[0034]FIG. 2 details the functional structure of a novel base station

[0035]FIG. 3 details another embodiment of the base station

[0036]FIG. 4 illustrates the physical structure of a base station.

[0037]FIG. 5 details a cellular to cellular link

[0038]FIG. 6 details a cellular to regular phone link

[0039]FIG. 7 details a link to an IP phone

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0040] A preferred embodiment of the present invention will now bedescribed by way of example and with reference to the accompanyingdrawings.

[0041] Some of the features in the example refer to voice transfer. Itis to be understood, however, that the technology in the presentdisclosure may be used for the transmission of voice, data, multimediaor a combination thereof.

[0042]FIG. 1 illustrates a distributed cellular network providing, inthis example, communications between a mobile user 11, a fixed user 12and a fixed user 13.

[0043] A communication network may include, for example, a cellularnetwork 22, a telephone network 23 and an Internet network 24, alllinked to each other.

[0044] Throughout the present disclosure, Internet refers to any IPnetwork, that may be for example the Internet or an Intranet.

[0045] User 11 is connected through a regular base station 21 to thecellular network 22. Users 12 and 13 are each connected to the telephonenetwork 23 and an Internet network 24, respectively. Since all thesenetworks are connected to each other, communication links may beprovided between the above users. The link to user 11 is wireless,whereas the link to user 12 is wired. The link to user 13 may beimplemented with various means.

[0046] An existing network may include, for example, an IP network, suchas the Internet, or Internet over cables, or a wired telephone network.Voice communication may be conducted in a voice over IP method using aknown technology. Basically, the voice is digitized, sometimescompressed, and cut into packets of data.

[0047] The packets are sent over an IP network to their destination. Itis possible that some packets are lost during the routing, and that thepackets are received in a different order. However, if not too manypackets are lost, the voice quality remains OK. A buffer is usuallyenough to compensate for the re-ordering of packets.

[0048] The above description refers to communications systems as knownin the art.

[0049] The novel approach allows to expand the above network, forexample with the addition of new base stations 41, 42 and 43.

[0050] The add-on base stations 41, 42 and 43 illustrate three types ofadditions to a cellular network. These are three ways the public canparticipate in the network to enhance its capabilities.

[0051] Add-on base station 41 allows to connect a mobile user (notshown) to the existing telephone network 23. The device includes awireless link with an antenna to connect to a mobile user, and a wiredlink to connect to an existing communication network.

[0052] This base station may be owned and operated by an independentperson or organization. Once this device, the base station 41, is boughtand operated by its owner, it generates a wireless cell in itssurroundings. The device will connect a mobile user in that cell to thetelephone network 23, and to any other network and/or user that may beconnected to network 23, either directly or indirectly.

[0053] Any person or firm or other entity that has a telephone line (aconnection to network 23) can buy an add-on base station 41 and connectit to the phone line, to create a new cell in the communication network.Thus, the public, on their own initiative, may add wireless cells to thenetwork.

[0054] Thus, our box achieves the function of a cellular base station ina distributed cellular network. It is also a micro-center for routingcalls, as detailed below.

[0055] The owner of the box connects it to an IP network to expand theexisting cellular infrastructure—now a user can connect through the newbase station to an Internet, to establish a link with a remote user.

[0056] It is assumed that all new base stations are connected to anInternet, since it is in widespread use. A user may connect to anInternet in various ways, for example using a telephone line, a cable TVchannel, wireless links etc.

[0057] Possible Internet links include the package delivery link and theTCP. Voice links usually use the former link, since in the latter theremay be a delay.

[0058] In a highly populated area, where there are many phone lines anda numerous population, there is a great probability that many peoplewill buy the novel base stations to generate many new wireless cells.

[0059] Thus, new base station 41 adds a new wireless cell in a locationwhere there is available a link to the telephone network 23 (a phoneline).

[0060] Base station 42 illustrates another type of network enhancement.It connects between an Internet 24 and the telephone net 23. This allowsa remote caller (not shown) to place a call to a phone in theneighborhood of base station 42: That remote caller connects basestation 42 over the Internet 24, and requires a connection to a phoneclose to that base station.

[0061] This achieves a lower cost communication link, since it comprisesan Internet link that is low cost, and a local phone call from basestation 42. It avoids the high cost of long distance phone calls. Thistype of base station is useful in the implementation of the presentinvention.

[0062] New base station 43 illustrates yet another type of networkenhancement. It generates a wireless cell that is directly connected toan Internet 24.

[0063] Thus, new base station 43 adds a new wireless cell in a locationwhere there is available a link to an Internet network 24.

[0064] The system uses the existing infrastructure, for example cableTV, Internet connections and phone networks to provide additionalwireless coverage. The above detailed structure and method may be usedfor other networks as well. These may include, among others, wirelesslinks, satellite links, cable TV links, fiber-optics or a combinationthereof.

[0065] Thus, new base stations 41, 42 and 43 allow to use the existingtelecommunication infrastructure in developed areas, to enhance thecellular network.

[0066] Private individuals or firms or other entities that have accessto existing communication channels and do not use those channels all thetime, may contribute to a cellular network by providing access to thosechannels. The novel system includes means to offer an incentive topeople, to motivate them to install and operate the base stations. Theseinclude means for collecting a payment for services rendered with thebase station.

[0067] Thus, it is possible to install or expand a cellular networkwithout the need for a large investment in infrastructure. Rather, thenew network is based on the existing infrastructure, for example atelephone network, a wireless network, Internet or a combinationthereof. Usually, existing networks have spare capacity. A user does notspeak all the time. Therefore, existing networks offer a great potentialfor expansion, by supporting new cellular networks.

[0068] Prior art cellular systems are easier to install in sparselypopulated areas, where there is no problem of interference, basestations installation etc. These systems are much more difficult toinstall in towns or other highly populated areas, where there are theproblems cited above. The present invention solves the problem ofcellular installation and achieves best performance in the denselypopulated areas that were difficult to address in the past.

[0069] The very population that may have opposed to the cellular net,are now helping the setting up of the new cellular network. According tothe new concept, small cells are thus created in cities or otherpopulated areas.

[0070] The maintenance cost is greatly reduced. The system operator isno longer responsible for the maintenance of a multitude of basestations located in a highly populated urban area. Rather, each owner ofa private base station is interested to keep his/her equipment inworking order. If there is a problem, the owner will see to repairs or areplacement.

[0071] In a preferred embodiment, simple and low cost base stations areused, that are expendable—when a malfunction is detected in a basestation, the unit is discarded and replaced with a new one.

[0072] The novel approach or method allows for a rapid deployment of acellular network. There is no time-consuming work to be done, to createa new infrastructure from zero.

[0073] The new system does not need a plurality of large switchboards tomake all the required connections. In prior art systems, as the numberof cells increases, the number and complexity of switchboards increasesas well. There is a large number of concurrent calls that have to besupported. This adds to the cost of setting up and operating a cellularnetwork.

[0074] The new system, however, uses the switchboards in the existinginfrastructure for call switching. Therefore, there is no need to addcostly switchboards.

[0075] There is a need for a coordination center that issues informationrelating to completing a call as required. Alternately, a plurality ofcenters may be used. These centers only provide information prior to acall, and do not take part in the actual link being formed. Thus,simpler and lower cost centers are required. This novel feature mayachieve a large reduction in the investment required to install orexpand a cellular network.

[0076] The centers store information for each base station, includingthe telephone number used by that station. This information may beadvantageously used to generate new links, to help one user to locate anIP base close to the desired destination.

[0077] The novel centers are also responsible for price setting, asdetermined by an operator there. The information regarding prices of useof the net and the additional, private base stations, is disseminated asdigital documents encrypted so as to prevent tampering with.

[0078] The centers are also responsible for tracking down malfunctionsin the cellular network. If a base station would not respond or wouldnot operate correctly, that information is brought to the attention ofthe center by related parties. The center will disseminate thatinformation, to help user form communication links with reliablechannels and base stations only.

[0079] The new centers may initiate calls to the various base stations,to verify their correct operation. Thus, the new cellular centerscorrelate and guide the operation of the users in the net, in real time.

[0080] Usually, a link will be formed with one switchboard at the source(the person who initiated the call) and a switchboard at thedestination. Additional switchboards are usually needed in between theabove switchboards. These are existing switchboards, that are part ofthe existing infrastructure.

[0081] The cellular links thus formed may be used for various purposes,for example to transmit voice or data.

[0082] A problem in a large network is the coordination of all theadditions to the cellular network. One can appreciate that a multitudeof cells, provided by many people, may be difficult to use and wouldrequire complex systems to route all the calls taking placeconcurrently. Usually, this would require a plurality of largeswitchboards to make all the required connections.

[0083] A novel approach uses a cellular coordination center 3 that doesnot perform the actual call switching. Rather, the new center 3 justprovides the information required for making a call. Center 3 (or anetwork of such centers) stores information regarding the various basestations, their location and coverage, availability and connections.When a user places a call, he demands information from center 3. Center3 provides the required information for placing a call, including a basestation close to the desired destination and more, as detailed below.

[0084] After providing the information to the caller, center 3 does notparticipate in the actual call routing; rather, this is performed by thecaller, using the existing network infrastructure. Thus the workload onthe center 3 is greatly reduced. Smaller, simpler and lower costswitchboards or cellular coordination centers may be used.

[0085] In some cases, the switchboards may be eliminated altogether.

[0086] A first user is given an Internet address of the other party andmay connect it directly. This achieves a direct link from one basestation to another, through IP. It may also be possible to connect usersthrough the same base station.

[0087] The phones of the network are basically similar to existingcellular handsets, except minor changes as detailed below.

[0088] Regarding the base stations: In prior art cellular networks, theswitchboards are always necessary in order to connect between cellularphones.

[0089] In the new system, communications may take place between cellularphones without the intervention of switchboards. This may result infaster, more effective communications.

[0090] Add-on base stations can be installed and owned by the cellularnetwork operator, but in a preferred embodiment, the base stations aresold with the cellular phone, or without it, to anyone- private personsor firms for example.

[0091] People will have an incentive to connect the base station intheir home/office, since they will get royalties from the cellularnetwork operator.

[0092] Preferably, the size and shape of an add-on base station issimilar to that of a cordless telephone base. This may achieve an easyto use device, whose operation is familiar to the user.

[0093] Structure and operation of the cellular center 3

[0094] Unlike presently used cellular centers, the center 3 of the novelnetwork does not need to carry the role of a switchboard. Existingswitchboards in a cellular or phone system may be used as usual, as wellas regular IP routing. The new center 3 coordinates the operation of thenew base stations like 41 and 43 as illustrated.

[0095] The duties of the cellular centers 3 include, among others:

[0096] a) Network integration and planning

[0097] b) Implementing a price policy.

[0098] c) Network operability.

[0099] d) Manager of phone locator. (In case of incoming calls).

DETAILED DESCRIPTION

[0100] a) The Cellular center 3 knows the current physical location ofall add-on base stations, and is aware of the status of each basestation (i.e. is available or not available, optionally processing acall etc.).

[0101] There may be a trade-off between the desire to keep the centerupdated, and the need not to overload it. If too high a frequency ofreporting to the center is used, this may achieve a center that isupdated to the last minute changes, however a large expensive center maybe required.

[0102] Alternately, it is possible to limit the rate of updates and thetype of events that require a report to center. The center does not haveto know of any minute change in a base station. For example, if a basestation is busy, but the center is not aware of it, the user may use analternative base station.

[0103] b) The cellular center is responsible for the price policy. Itdetermines and publishes the cost for each operation over the network.The updated information may be transferred over an Internet, or may beavailable to add-on base stations. The information may be dispersedbetween units in the network. In each transaction, the parties theretowill check the date of each price list. The more updated price list willbe transferred to the other party. Thus, the new price list or policywill gradually expand throughout the network.

[0104] c) The cellular center is responsible to actively check, once ina while, the availability of base stations and their operability (see ifthey work properly).

[0105] d) One of the main tasks of the cellular center is to give thefunction: when given a “cellular phone number”, it is able to return theIP address of a base station, that has radio contact with it.Alternately, it may return a message that the phone is in the “out ofcoverage area”.

[0106] A call processing method is detailed below with reference toFIGS. 5, 6 and 7.

[0107] Data Security

[0108] Each phone, base station and the cellular center 3 may have theirown digital certificate, which binds a cryptographic public key, with anidentifier. The certificate may also contain information such as theirphone number or identity. The extra information can also be included inother digitally signed digital documents.

[0109] In this way the packets of voice originating from the phone, canbe encrypted by the destination public key to the other phone, ensuringprivacy. They can also (or alternatively) signed by the originator'sprivate key, to ensure authentication (and possibly non-repudiation).

[0110] A phone user may require that all incoming or outgoing calls beauthenticated and/or encrypted.

[0111] The control channel includes the information exchanged betweenbase stations, phones and/or centers. The control channel can beencrypted at the base stations, the centers and/or the phones. The phonecan send back to the base station the necessary changes (such as a cellchange). The communication between the phone and its base station canalso be encrypted.

[0112] It is possible to preserve the anonymity of the caller and theaddressee, using the following method:

[0113] A. A caller sends a request to connect to a specific addressee,using a message encrypted with the public key of a center 3. The messagealso includes the identification of the caller. Nobody can read thismessage, since it is encrypted.

[0114] B. the center decrypts the message, identifies the caller and theaddressee.

[0115] C. the center composes a message for the addressee and encryptsit with the public key of the addressee. The message is then sent tobase stations that may be in contact with that addressee. The actualpolicy in use may vary from network to network. A search path may befollowed, according to information from past activity for example.

[0116] D. the base station transmits the message “as is” or in amodified form. In any case, the encrypted section is preserved—the basestation and other phones in the area will not know who is the caller andwho is the addressee.

[0117] E. only the designated addressee will be capable to decrypt themessage, and will be thus notified of the attempted connection. Otherphones, that do not possess the required private key, will not be ableto decrypt the message, and will thus know that the message was notaddressed to them.

[0118] F. if the addressee decides to answer the call, he sends aresponse message, encrypted with a known public key—for example that ofthe center, or may ask the base station to reply to that call.

[0119] G. the center sends a message to the caller, with information toallow him to implement the connection with the addressee. In anotherembodiment of the invention, the addressee may contact directly thecaller.

[0120] The above method preserves the anonymity of the caller and theaddressee. Although the communication may pass through variousswitchboards and base stations, none will know the identity of theparties to the conversation, except the cellular center.

[0121] The center may know about the inquiry, but it will not knowwhether a communication actually did take place between the partiesinvolved.

[0122] The subsequent dialog or data transfer may be en clair; it isbelieved that the identity of the parties to a communication may be moreimportant than the actual information being transferred. Thus, for aneavesdropper the dialog itself may be meaningless if the identity of theparties involved is kept secret.

[0123] Thus, all the cellular phones are open and continuously receivethe various messages transmitted from a base station in step (D) above.The messages decryption takes computer power, so that it may waste thebattery power.

[0124] To save on battery, the phones may be divided into a predefinednumber of groups, for example 1,000 groups. The message to a phone mayinclude a short header that indicates the addressee group. This is ashort number that is easy to decrypt; a telephone will decrypt the wholemessage only if the header of the message corresponds to the group ofthat phone.

[0125] To improve security, the cellular center 3 may accept a requestto locate phones (locate nearest IP) only from base stations. The basestations that help to locate a phone, (or the phone itself) may do soonly if requested by the cellular center, or by some other authorizedentity. Thus, in step (B) the center checks the authorization of thecaller to sent the request; only if the caller is authorized, then thecenter will proceed to execute step (B); otherwise go to step (H). Theauthorization may be checked using authorization tables kept at thecenter for that purpose.

[0126] The above means help achieve privacy in a distributed network—itprevents a user's location from being divulged to others.

[0127] The cellular center 3 can issue a certificate (an operatinglicense) or another digital document, to the effect that “thisphone/base station is part of my network and is in working order” to allthe devices connected thereto. The certificates may have a shortexpiration date, of 1 day for example.

[0128] This gives the center 3 control over the phones and basestations, that may be disconnected at short notice.

[0129] This allows a phone to ask the services of a base station only ifit has an updated operating license. Similarly, a base station canverify that the phone is operating properly.

[0130] This is one way that a cellular center can exclude “badlybehaving” devices from the network. Devices may be otherwisedisconnected or excluded for other reasons, as programmed into thecenter's operating program.

[0131] Billing

[0132] An important aspect of the present invention is the means forpaying to the owner of the add-on base station for his/her services.This provides the incentive for acquiring and operating these basestations.

[0133] Since the sessions are encrypted, the payment process can beperformed in a way similar to that used with smart cards in prior art.An encrypted session is akin to a point to point, secure link.

[0134] Thus, the base station includes means for accepting a payment andfor displaying to the user information relating to the paymentsreceived.

[0135] Using encryption and digital documents, it is possible toreliably implement the payment method as detailed in the presentdisclosure, while preventing impostors or others who may present falsepayment means. This may help prevent stealing of calls, that is aproblem in present systems.

[0136] Further means to prevent calls stealing is the caller ID anddestination ID. That is, in the novel system both the identity of thecaller and the destination may be known. This may prevent or intimidatea potential thief, who may know that his actions will be recorded anddetected.

[0137] A possible method of billing is by way of money or tokens.Digital documents may be used that correspond to cash money or to acredit or right to use the network at someone's expense, or mayrepresent phone tokens having a specific monetary value each. Thesedocuments may be encrypted or signed so as to allow the owner of thebase station to receive payment for services rendered.

[0138] The phone may download tokens or money from the center or from aplastic card or a smart card or by other means. These payment means maybe stored in the phone for subsequent use.

[0139] When originating a call, or otherwise as stated in the cellularcenter policy, the phone would send tokens to the base stations in theway to the other phone.

[0140] In this way he pays for the session on-line and in real time.

[0141] The center can profit since for a certain amount of money it willgive a certain amount of tokens (and take its profit).

[0142] Base stations receive payment, and can later redeem the tokensfrom the cellular center back to money, or receive new tokens for theirowner instead, for the owner's use in his/her communications over theircellular phone. Redeem of the tokens is a preferred embodiments, sincein this method the center's profit is assured.

[0143] The billing policy can be written digitally by way of a digitaldocument, with a date (and a short expiry date), signed by the cellularcenter. This policy would be stored in all base stations and phones, andthey set the prices (by means of tokens) that the phones pay.

[0144] When two units interact, they can compare the time stamps or theversion of the policy held by each unit. Thus the policy is updated asnecessary and there would not be any dispute between the parties.

[0145] The information may be dispersed between units in the network. Ineach transaction, the parties thereto will check the date of each pricelist. The more updated price list will be transferred to the otherparty. Thus, the new price list or policy will gradually expandthroughout the network.

[0146] The billing unit can be a “black box” inside each apparatus. Thisblack box can be tamper-free, including means to destroy its contents ordelete the information therein, if someone tries to tamper with it. Thisensures that it can be trusted to work under commands given in policydocuments.

[0147] The billing unit may be implemented as part of a call controller54 in the base station, see FIG. 2. In another embodiment, the black boxfunction may be contained within a smart card.

[0148] The above structure and method may be either used to enhance anexisting cellular system or to create a new cellular system altogether.

[0149]FIG. 2 details, by way of example, the functional structure of anovel base station (like base station 41, 42 or 43 of FIG. 1). The basicfunction of the station is to connect a first channel 51 with a secondchannel 52. Either channel may be wired or wireless, using varioustechnologies.

[0150] The channel electronic means 53 implements the actualcommunications to connect between the channels 51 and 52. A callcontroller 54 supervises and controls the operation of means 53,according to commands received from a user through the control inputs541 for the base station.

[0151] A billing processor 55 computes the fee or payment the basestation owner is entitled to, according to the amount of traffic on thechannels 51, 52, and the method or policy as set in the billingdocument.

[0152] Thus, as more communication services are provided to the public,the owner of the base station will receive a larger fee accordingly.

[0153] A display 56 may be used to display the payment due or paymentreceived for the calls placed by other users.

[0154] A novel feature of the base station is a unique property in eachdevice. This unique property may be stored, for example, in either thecall controller 54 or the billing processor 55.

[0155] This unique property allows to use the base station as an add-ondevice. In prior art, each phone had an unique identity, however thebase stations had no unique properties. Each base station in prior artwas distinguished based on its fixed location and wiring; there were nodistinguishing means in the base station itself.

[0156] In the novel approach according to the present invention,however, there are base stations that are add-on units to be added to anetwork by various persons or firms. The location of each such unit isnot known a priori; its very existence has to be announced to thenetwork. A base station with an unique identity allows the network tokeep track of the addition of each new base station. The unique identityhelps manage the expanding network.

[0157] Various means may be used to achieve the unique identity of eachadd-on base station. For example, an unique number may be stored inmemory means in units 54 or 55. Alternately, a digital document may bestored therein. A smart card with an unique number or document may beinserted in the base station to activate it.

[0158] A plurality of users may be served using wideband channels havingthe capability to serve several users at once. For example, channel 51may be a wireless channel capable of communicating with several usersusing TDMA or FDMA or CDMA. Channel 52 may be an Internet connectioncapable of connecting to several destinations simultaneously.

[0159] Alternately, more than two channels may be used. This may allow abase station to concurrently communicate with more users and/ornetworks.

[0160] It is also possible to have other types of channels, for examplewired phone lines.

[0161]FIG. 3 details another embodiment of the base station. The RFchannel includes an antenna 61 and an RF unit 62. The main box 63includes the electronics for connecting the RF channel to the phone lineconnection 64 and the IP connection 65. In a preferred embodiment, thephone line connection 64 is optional. An add-on base station may onlyinclude the RF channel (to connect to a mobile user in a cellularwireless system) and the IP connection 65. The base station may also beconnected to an optional source of electrical power.

[0162] The size of the base station can be not larger than a regularcellular phone. It has the following components:

[0163] a) Main box

[0164] b) IP connection

[0165] c) antenna

[0166] d) phone line connection

[0167] Some of the above components may be optional, as required for thedesired function as an add-on to a cellular network.

[0168]FIG. 4 illustrates an embodiment of the physical structure of anovel base station, including a cellular phone 71 and a base 72. Aconnector 721 is used to connect the two devices. The owner may use thecellular phone as usual, to communicate as desired. When not in use,he/she may insert the phone 71 into the base 72 to form a base station:the phone 71 communicates with mobile users, and the base 72 isconnected to wired networks through a phone line connection 64 and/or anIP connection 65. The device may further include mains power connection722.

[0169] This system requires a modified phone, that has a capability tooperate as a base station, both in transmit and receive modes. Incellular systems, the mobile phones transmit in a first frequency bandand receive in a second frequency band, whereas the base stationtransmits in the second frequency band and receives in the first band.

[0170] Thus, a cellular phone cannot communicate directly with anotherphone. Accordingly, in the present invention, the phone 71 includesmeans for transmitting and receiving in the way used by base stationswhen it acts as a relay station.

[0171] Moreover, the phone 71 further includes means for transmittingand receiving control signals as required in a cellular network, toestablish a communication link with a mobile phone and control thatcommunication. The control signals may include, for example, powercontrol, link establishment and disconnection. The control signals arespecific to each cellular network like GSM, AMPS, CDMA etc.

[0172] The phone 71 may include means for performing one cellular linkat a time, or it may include means for communicating at once withseveral mobile phones. In the latter case, it will function as a basestation for several mobile phones located in its surroundings.

[0173] The above description refers to one embodiment, where the RF linkis implemented with a modified cellular phone 71. In another embodiment(see FIGS. 2 and 3), no cellular phone is used to implement the RF linkwith other phones. Rather, a complete base station includes all the RFtransmit and receive means to allow it to communicate with a mobilecellular phone. The base station may include means to allow it toconcurrently communicate with several mobile phones.

[0174] Furthermore, the base station may include means for charging abattery in the cellular phone. Thus, as the phone is inserted in thebase, its battery is charged and concurrently the phone may be also usedto expand a cellular network.

[0175]FIG. 5 details a cellular to cellular link that may be implementedover the system as illustrated in FIG. 1. A link may be establishedbetween a first (mobile) user 11 and a second (mobile) user 14. User 11communicates with new base station 43, that is connected to an Internetnetwork 24.

[0176] User 14, who is located in another area, communicates with newbase station 44, that is also connected to an Internet network 24. Thus,a communication link is established between users 11 and 14 through theIP network 24. This is a low cost, fast link.

[0177] A call processing method

[0178] Following is detailed a method for conducting a cellular tocellular call over the network.

[0179] A. The phone 11 which is initiating the call, is accessing thenearest base station 43 by means of radio communication.

[0180] It identifies and requests a (voice) connection to the otherphone number 14. The number may be either en clair or encrypted. For anencrypted session—see details in the “Data Security” section.

[0181] B. The base station 43 then contacts the cellular center 3 (seeFIG. 1), asking the IP address of the nearest station 44 to thedestination phone number 14.

[0182] C. There are several possibilities:

[0183] C1. The cellular center 3 returns an answer, that the destinationis not available.

[0184] In this case either the base station 43 is notifying therequesting phone 11 of the situation, or the center returns an alternateIP address. The alternate IP address can be the destination voice mail,or a recorded message, for example: “The phone you have reached is notavailable right now, please try later.”

[0185] It is also possible that the IP indicates a link to advancedservices, such as “follow me” etc.

[0186] C2. The destination is available. In this case, it is possiblethat the return answer would come either directly from the base station44 that is in contact with the phone 14, or be returned by the center 3.

[0187] In case an IP was returned, the base station 42 contacts thedestination station over the network , and “calls” the phone 14.

[0188] If the phone 14 is taken off the hook, then packets of voice areexchanged between the base stations, and are forwarded from and to thephones 11 and 14, so that a phone session is established.

[0189] In case the phone 14 refused the call, the originator basestation 43 can try to locate the phone again through the center, or askto see if there is a voice mail IP from the center. The phone 14refusing the call can also state another IP or number where it may becontacted, or a voice mail.

[0190] To preserve the privacy of the addressee, the phone 14 may askthe center not to disclose its refusal. Rather, the center may announcethe caller that the addressee is not available.

[0191] Moving between cells (base stations)

[0192] Let us assume that a mobile phone has a link with a first basestation. It may happen, during the conversation, that the phone detectsthat it receives the first base station at a low power, that is at apower lower than a predefined threshold.

[0193] In that case, a program in the phone may run a background searchfor an alternate base station. If it finds a second base station at ahigher received power, then the phone will ask it to continue the call.It will send packets from the new station, and try to inform the oldstation of the change.

[0194] Alternately, the new base station can inform the old base stationof the transfer of the call to it.

[0195] The other party's base station is informed by the phone or by thebase station of the new IP address of new base station.

[0196] Thus the link is disconnected from the first base station and anew connection is established with the second base station, to improvethe quality of the link. It is assumed that a higher received powerindicates a link with an improved communication quality.

[0197] Locating base stations

[0198] After a base station was bought by a person or entity, a stage ofactivating the base station is to be performed. The device is activatedwhen it is connected to and integrated within the cellular network.

[0199] The location of base station can be made known to the cellularcenter 3 using various methods. Several ways are detailed below by wayof example.

[0200] 1. During the registration of a base station, the person thatregisters the base station would state its location.

[0201] 2. If the base station is connected to a phone line, its locationcan be found automatically from the number it is connected to.

[0202] 3. The station can “listen” to transmissions from other basestations nearby (whose location is already known), and forward theinformation regarding the identity of received base stations and thepower level of each such reception to the cellular center. Using thisinformation, the cellular center can estimate the location of the newbase station.

[0203] 4. Nearby stations (which are already known in the system) canlisten to a beacon or transmission from the new station and thus itslocation can be estimated.

[0204] 5. A low-cost GPS device (with or without earth radiocorrections) can be inserted into the base-stations, so that it wouldknow and report its location.

[0205] Method for locating the destination base IP

[0206] There are several methods to locate a phone.

[0207] 1. This can be done in a similar fashion to what is done atpresent. Since the cellular center knows the location of base stations,it can start a search for the phone from the last place it was known tobe.

[0208] 2. Otherwise, the phone could be “paged” over paging channels,and the phone would reply to the nearest base station, and this replywould be forwarded by that base station to the cellular center.

[0209] 3. A phone may be required to send a beacon once in a while tothe nearest base station, so that the center may know its location.

[0210] 4. The network may be divided into geographical zones. A city maybe a zone, for example. The phone may be required to announce the centerwhen it crosses the boundaries of zones.

[0211] Methods for achieving data security and for billing were detailedabove.

[0212] Secure means as detailed in the “Data Security” section above maybe used, to preserve the anonymity of the caller and the addressee. Onlythe cellular center will know the identity of the parties to aconversation. Even the center will not know whether the conversationactually took place.

[0213]FIG. 6 details a cellular to regular phone link. A link isestablished between a first (mobile) user 11 and a second (fixed) user12. User 11 communicates with new base station 43, that is connected toan Internet network 24.

[0214] User 12, who is located in another area, is connected to theexisting telephone network 23.

[0215] A new base station 42 connects (bridges) between an Internetnetwork 24 and the existing telephone network 23, wherein the point ofentry to the telephone network 23 is preferably in a location close tothat of user 12, so as to achieve a local, or low cost, phone link.Thus, base station 42 achieves a low cost connection between users 11and 12.

[0216] A cellular center 3 (see FIG. 1) may direct user 11 to a basestation that is close to the call destination (to user 12).

[0217] A call processing method—cellular to regular phone

[0218] Following is detailed a method for conducting a cellular phone toa regular phone call over the network.

[0219] The conversation goes the same as illustrated above for thecellular to cellular link with reference to FIG. 5, however the center 3will not return the IP of the base station nearest the destinationphone. Rather, the center 3 calculates the nearest base station 42 tothe destination phone number 12 and give its IP.

[0220] That station 42 is the one that is connected to the phone system23, and has agreed to process calls for the cellular system. Theoriginator base station 43 would connect to the base station 42, whichwould act as a gateway station.

[0221] The line module in the gateway station 42 will play the role of acellular phone. The phone conversation can be encrypted up to thegateway station.

[0222] A call processing method—regular phone to cellular

[0223] Several methods may be used to implement such a call.

[0224] 1. If there is cooperation with a telephone company, the cellularcenter 3 can inform it of the phone numbers of all the base stations 42that have agreed to be a gateway station. The regular phone user candial a number with a special prefix, and the call would be routed to thenearest gateway station 42 whose line is available.

[0225] The gateway station can know of the destination by means ofcaller ID, DTMF, other digital way, or that the caller would get anothertone signal from the gateway station, and could dial the rest of thenumber by DTMF identification.

[0226] 2. Otherwise, it is believed that the telephone company will showat least a measure of cooperation, to the effect that it will contactthe caller to the nearest gateway station number. Then, the dialing canbe completed with the gateway station identifying the DTMF from thecaller.

[0227] Since we assume many people will use the new cellular system, itis a reasonable assumption that there will be a gateway stationavailable in the same telephone switchboard of the destination phone, sothe call would be local.

[0228] 3. If there is no cooperation from the telephone company, a 1-800number can be set up, so that someone could find the nearest gatewaystation near him. In other words, the caller would have to call directlyto some gateway station, and continue dialing from there, by DTMF forexample. The gateway may provide a dial tone to assist this dialing. Thegateway may use automatic DTMF recognition for that purpose.

[0229] The gateway base station in this case is playing the caller phoneto the network. It may also add information such as called ID.

[0230] Billing in this case is by the receiver phone, or otherwise asset by policy of the cellular center. It is possible that the callerwould pay for the tokens, if the phone company bills him for their cost,and sends that amount to the cellular center. This enables the basestations to bill the cellular center later, if it is by prior agreement.

[0231]FIG. 7 details a link to an IP phone. A first (mobile) user 11 mayconnect to a second (fixed IP phone) user 13.

[0232] User 11 may connect either through base station 41 or basestation 43. The new base station 43 is directly connected to an Internetnetwork 24. The new base station 41 connects (bridges) between thecellular user 11 and the existing telephone network 23, which isconnected to Internet 24.

[0233] A call processing method—from an IP phone

[0234] Since calls are already over the IP network, people may prefer touse the IP network as their main phone network. Special apparatus couldbe made to play the part of base station and phones, all in a regularphones case.

[0235] Otherwise, this may be done with PCs with software and with orwithout hardware (possibly a smart card—to do all the black box part).

[0236] Communication to/from an IP phone is the same as regular cellularphones, if implemented in this way, and can also be as outside phoneswhich contact a base station that agreed to act as an IP gateway.

[0237] Remarks

[0238] Various embodiments of the present invention are possible.Following are several examples.

[0239] 1. It is possible to create centers of access to the system,which may contain an array of base stations that will function asgateway stations. It is also possible to build antenna towers in areasfar from urban areas such as roads.

[0240] 2. It is possible to include relay option means in cellularphones, in such way that if a phone is far from a cell, but there is another phone in the way that receives both, it can act as a relay. Thisstructure is better suited for car phones. It can be also used inhandheld phones. Tokens can be also paid to the relay station that takespart in a communication link.

[0241] 3. Large systems can be subdivided into smaller systems or bylocation or by country or another geographical criterion. Connectionbetween those systems can also be done by IP means, if desired.

[0242] 4. The add-on base stations may be installed in various vehicles.This may achieve cellular coverage in areas that may otherwise not becovered. The device may include means to install in a vehicle, includinguse of an installed antenna and the power source in the car. Thus,parked cars may be used as relay stations, with a cellular phoneinstalled in the car acting as an add-on base station.

[0243] 5. The mobile base stations may include wireless means to connectto each other. A linked channel may thus be achieved, with the basestations acting as relay stations. This may allow communications wherethe fixed base stations are far apart from each other. This structureallows for a link between moving cars.

[0244] 6. The add-on base stations may allow surfing an Internet. Toachieve this, the base may include communication means for data, voiceand/or multimedia. Any type of information may be transferred.

[0245] 7. The system may be used for encrypted E-mail. An advantage ofthe present system is that the identity of the parties to that E-mailcorrespondence are kept secret from the base stations and other factorsin the net. Only the center knows the identity of the parties to theE-mail. The technology may also be used in E-commerce. It preserves theprivacy of the parties to a transaction.

[0246] 8. The system may use a cellular center to coordinate theconnections between users. Alternately, a distributed center network maybe used.

[0247] Advantages

[0248] 1. Lower radiation base stations

[0249] Since cellular cells (each base station) may be quite close toeach other, the cellular cells can be small, and reduce the transmissionpower needed for the base stations, resulting in lower radiation.

[0250] 2. Lower radiation mobile phones

[0251] Since base station are closer, the distance from a mobile phoneto a base station is shorter. Thus, the mobile phone may transmit at alower power.

[0252] 3. Low cost deployment

[0253] There is no need for a new infrastructure. That is achieved withlow cost base stations, that can be mass produced.

[0254] Since people may put these low radiation stations in their homesor offices, there may be no need for licenses from authorities toinstall these devices. There may be no need to ask for a license toinstall a high power transmitter or a large antenna.

[0255] Since routing may be done for example by IP routing, there is noneed for large switchboards. Actually there may be no need for ANYswitchboard. Only computers that connect to the network are required, toact as the cellular centers. There is no need for highly trainedpersonnel to deploy the network.

[0256] 4. Quick, no hassle deployment

[0257] Since the system is using existing infrastructure, there is onlyneed to put and connect base stations, which ordinary people can dothemselves, just like connecting a wireless phone, the deployment israpid, without the need to construct and install large antennas.

[0258] 5. Lower cost of operation

[0259] There is no need to take care of a large infrastructure and itsoverhead, like switchboards, carrier lines, etc. There is no need forpersonnel or highly trained personnel to manage the network. Since theequipment is so cheap, it can be just replaced.

[0260] 6. Cheap air-fare

[0261] Since the overall cost is low, the prices for the end user can below, and the possibility to earn money from base stations, may be anincentive. Also, as described, connections to/from regular phone systemmay be done as local calls. Therefore, there is additional savings inpayment to phone companies.

[0262] It will be recognized that the foregoing is but one example of anapparatus and method within the scope of the present invention and thatvarious modifications will occur to those skilled in the art uponreading the disclosure set forth hereinbefore.

What is claimed is:
 1. In a cellular network system, an add-on basestation comprising: A. a first channel for connecting to a customer'sphone; B. a second channel for connecting to a network; C. circuits forconnecting the customer's phone to a destination on the network; and D.billing means for collecting a payment for services related toconnecting the customer's phone to the network.
 2. The base stationaccording to claim 1 , wherein the customer's phone is connected througha wireless link.
 3. The base station according to claim 2 , wherein thefirst channel further includes means for generating and receivingcontrol signals as required to communicate with the wireless phone. 4.The base station according to claim 1 , wherein the second channelconnects to an IP network such as an Internet or Internet over cables,or to a wired telephone network.
 5. The base station according to claim1 , wherein the billing means include means for receiving payments inthe form of digital documents.
 6. The base station according to claim 5, wherein the digital documents include tokens, digital cash or a creditor right to use the network.
 7. The base station according to claim 1 ,further including storage means for storing digital certificates.
 8. Thebase station according to claim 7 , wherein the certificate binds acryptographic public key with an identifier.
 9. The base stationaccording to claim 7 , wherein the certificate includes an operatinglicense for the base station.
 10. The base station according to claim 1, further including unique identification means for each base station.11. A cellular network system comprising: A. a center for forwardinginformation as required to establish an IP connection between twoparties; B. a plurality of cellular phones capable of connecting over acellular wireless network; C. a plurality of base stations, connected toan IP network and including means for communicating with the cellularphones over a wireless channel and means for routing messages over theIP network.
 12. The cellular network system according to claim 11 ,wherein the center includes means for keeping track in real time of thecellular phones that can be reached through each one of the basestations.
 13. The cellular network system according to claim 11 ,wherein at least one of the base stations further includes billing meansfor collecting a payment for services related to connecting the cellularphone to the IP network.
 14. The cellular network system according toclaim 11 , wherein at least one of the base stations further includesmeans for its operation from a mobile base.
 15. The cellular networksystem according to claim 11 , wherein at least one of the base stationsfurther includes communication means for data, voice and/or multimedia.16. The cellular network system according to claim 13 , wherein thebilling means include means for collecting payment in the form oftokens, digital cash, a credit and/or rights to use the network.
 17. Thecellular network system according to claim 13 , wherein the billingmeans include smart card means for collecting the payment.
 18. A methodto establish a link between a caller and an addressee, while preservingthe anonymity of the caller and the addressee, comprising the steps of:A. The caller sends a request to a cellular center requesting to connectto a specific addressee, using a message encrypted with the public keyof the center. The message also includes the identification of thecaller; B. the center decrypts the message, identifies the caller andthe addressee; C. the center composes a message for the addressee andencrypts it with the public key of the addressee. The message is thensent to base stations that may be in contact with that addressee; D. thebase station transmits the message “as is” or in a modified form. In anycase, the encrypted section is preserved—the base station and otherphones in the area will not know who is the caller and who is theaddressee; E. only the designated addressee will be capable to decryptthe message, and will be thus notified of the attempted connection.Other phones, that do not possess the required private key, will not beable to decrypt the message, and will thus know that the message was notaddressed to them. F. if the addressee decides to answer the call, hesends a response message, encrypted with a known public key—for examplethat of the center, or asks the base station to reply to the call.Otherwise—go to step (H). G. the center sends a message to the caller,with information to allow him to implement the connection with theaddressee, or the addressee contacts the caller directly; H. end. 19.The method according to claim 18 , wherein in step (B) the center checksthe authorization of the caller to sent the request; only if the calleris authorized, then the center will proceed to execute step (B);otherwise go to step (H).